What is the advantage of having a tankless water heater?

Shower spraying hot water

Why choose a tankless water heater?

The tankless water heater is making its way into more homes every day. So what makes tankless water heaters so good that everybody seems to want one? Are tankless water heaters better? Just what is it that makes them better than the standard storage tank water heaters?

When replacing the water heater in your home, it is a small investment that requires consideration of three main factors – Cost. Efficiency. Longevity. It is those three factors that have made many homeowners switch to the tankless water heater. But there isn’t such a thing as the ideal, perfect appliance, and the tankless water heater is no exception. The advantages do deserve a review though:

Over time, a tankless water heater will save you money
Energy efficiency up to $100 annually for gas and $44 for electric models
Up to a 30-year lifespan
Less space needed
On demand hot water

But as with all good things, there are some disadvantages with the tankless water heater too:

  • Initial purchase is higher
  • Tankless water heater installation may require extra electrical and plumbing work
  • The output of hot water can be challenging when there are multiple areas of need

We’re going to answer some specific questions about why a tankless water heater vs tank may be better for some, yet may not be the best answer for every home.

How does a tankless water heater work?

Tankless water heater means there isn’t any storage tank like the traditional water heater we have grown accustomed to having in our homes. Instead, the process of getting hot water has been simplified. Turn on the hot water faucet and you get instant hot water as the cold water travels through piping into the unit. It is then heated by electricity or gas, depending on which type of tankless water heater you have.

A tankless water heater doesn’t require waiting for the water to fill up the tank. Instead, two to five gallons of water are heated instantly. For a home where hot water is needed in abundance, like lots of showers, dishwasher, and laundry all running at the same time, a gas tankless water heater would be the better choice.

Is a tankless water heater gas or electric?

Tankless water heaters are available with both electric and gas power. One isn’t specifically better than the other and the decision of which to get needs to be determined by the expected hot water usage along with the following factors taken into consideration as well:

  • The availability of adequate electrical supply or natural/propane gas for the high output required by a tankless water heater
  • The initial cost of installation
  • The cost for an electric or gas tankless water heater of the appropriate size
  • The water usage habits of the household
  • The cost difference of electricity and gas for the area now and going forward
  • The desired location
  • Personal preference

Which tankless water heater is better?

Like anything new on the market, every year another manufacturer releases their version of a tankless water heater. Which brand is better will depend on what is the most important feature to your household.

  • Best overall tankless water heater: Rinnai RUR160iN
  • Best tankless water heater for a low price: EcoSmart Eco 18
  • Best electric tankless water heater: Rheem RTEX-24
  • Best point-of-use heater: Bosch Tronic 3000

How big of a tankless hot water heater do I need?

To choose the right size tankless water heater, the flow rate needs to be assessed along with the temperature rise, meaning the whole house or for one particular room.

Step One: How many water devices will need hot water and what is their flow rate. The desired flow rate is the expected demand for hot water.

Step Two: Decide the required temperature rise by subtracting the incoming water temperature from the output temperature.

Step Three: Choose the sizing with an average shower using 2.6 gallons at 104 to 106°, you want enough hot water for two showers simultaneously.

Do tankless water heaters need maintenance?

Yes, like tank storage water heaters, there is some level of maintenance that should be done.

Frequency of Cleaning

An annual flushing is needed with a tankless water heater, the same as with a tank storage water heater.

Exterior Maintenance

Wipe down the cover with a non-abrasive cleaner and a soft cloth to keep it dust-free and to help prevent rust from developing. The pipes should be inspected for possible cracks or splits in cold weather. If there is a PRV on your tankless water heater, test it occasionally.

Descaling a Tankless Water Heater

Start by disconnecting the power source and then close the cold and hot water shut-off valves. Open the PRV carefully and connect the flush kit hoses with the water service ports. Place a submersible pump in a bucket with the cold water connected to the pump and the hot water hose inside the bucket, and then pour four gallons of vinegar in the bucket. Open the cold and hot service ports and turn on the submersible pump.

Let the vinegar circulate through the water heater for one hour then turn the pump off and pour out the vinegar. Next, close the cold water service port and open the cold water shut-off valve to flush out the vinegar. Close the valve and allow the water to drain completely. Finish by closing the hot water port.

Close-up of tankless water heater

In Closing

How long does a tankless water heater last? A traditional tank storage water heater system will have a maximum life expectancy of six to 12 years. A tankless water heater has a life expectancy of 20 years or longer. The tankless water heater has parts that can be easily replaced that will extend that life expectancy. If you’re interested in learning more about tankless water heaters or having a tankless water heater installed, reach out to the Chattanooga Water Heater Co. team at 423-718-7342.